I have no idea how to adjust the thread, but I don't consider it a mortal sin if you leave it as is. After all the trouble to bring your drum back to life, I would play it if I were you. Those RK's have a fat woody sound that really cut through a large ensemble.

As a player, my approach to collecting is evenly balanced between securing a desirable sound quality and having an instrument of prominent or historic significance.

Hit Drum, Get Check!

+1 with kdg. The re-wrap, moisture damage, and re-cut edges relegate this drum to "players grade". In an odd way this has some advantages over a pristine original. You, and the grand kids for that matter, can play and enjoy this fine drum without worry. Have fun with it!